【单选题】一个p对极的三相交流线圈,有两个有效边在空间的电角度为170 。 ,则其对应的机械角度为 。
【单选题】It is said that ______ 2000 factories were closed down during the economic crisis.
【单选题】有关病毒癌基因正确的是
C.
正常细胞中的原癌基因与病毒中的癌基因是非同源的
【单选题】一个 p 对极的三相交流线圈,有两个有效边在空间的电角度为 170 。 ,则其对应的机械角度为 。
【单选题】Although the situation was tough during the economic crisis now things are beginning to ________.